Hey, know that down hill sign? Here it is: http://www.trafficsign.us/650/warn/w7-1.gif. When I was little, I used to think it was a robber sign. Think about it - the wheels are eyes, the hill part is a bandana over the mouth, the cab and trailer are a hat. I thought the percent indicated with each of these signs meant that was the percent chance you'd have, if you stopped on the road there, of getting robbed.